1. Field of the Invention
The present invention relates to pipe connectors, and more particularly to underwater well flowline connectors that may be actuated by remote control.
2. Description of the Prior Art
In many adverse environments and/or locations where adjacent ends of two pipes must be connected together, such as flowlines at subsea oil or gas wellheads, it is very difficult to adequately align the ends of the pipes so that a fluid-tight connection thereof can be achieved. Various types of apparatus and techniques have been employed or suggested for interconnecting the ends of subsea well flowlines, including equipment requiring the assistance of one or more divers, and systems involving apparatus that is operated by remote control through the use of television or sonar signals. The expense and the inherent dangers to life that are associated with diver-assisted techniques establishes them as less than totally satisfactory, and the depth at which a diver can work efficiently is presently limited to relatively shallow waters. Although some of the remotely-operated connection systems are, at least theoretically, operable at any depth, substantial difficulties have been experienced in maintaining close control, and hence proper functioning, of these mechanisms.
In an attempt to overcome the foregoing problems, the ends of the flowlines have been connected to separate fabricated structures, but not infrequently there is insufficient space in these structures to allow sufficient flexure of the flowlines to accommodate any misalignment thereof. Also, the flowline may be so stiff that they cannot be bent to force their ends into proper alignment. Forced alignment of the end of the flowline often causes undue stress on precision seals at the connections, and may cause such seals to fail. Hence, it is desirable to have a coupling between the two flowlines that can accommodate a certain amount of misalignment when they are connected. Some examples of flowline connectors of this type are disclosed in the U.S. Pat. No. 3,554,579 to Brown, No. 3,732,923 to Fowler, and No. 3,874,706 to Arnold.